Stone basement walls -resurface/repair help

We have a pre-1950's home with stone walls in most of the basement. It is probably almost three feet thick so I'm sure that structurally it is fine but the interior is starting to deteriorate. It sure is dusty down there! We want to resurface the wall and a salesperson at Menards recommended using mortar to do this (there are some pretty big gaps between the stones in places.) The mortar did seem to work OK where there were large gaps but I'm not sure we had the consistency right. We were told to mix it to the consistency of paste... Even though we actually VACUUMED the wall before starting the mortar didn't stick very well. Should
we have wet down the wall? Is there a better way to do this? (I think we ended up with more mortar on the floor than on the wall! LOL) And will the mortar work OK for smoothing out the wall, or is it really just for filling in gaps? Any suggestions would be GREATLY apppreciated!!! Thanks.

 

Typical Menards answer. Here is what he did not tell you. Add 1/4 cement mix and 1/3 sand to the morter mix. That will make it stick, and the second coat will allow you to make it smooth.

 

We have the same problem. We filled in the holes with mortar, then painted the walls with dry_lok brand waterproofer. It looks great. Now we are going to stud and dry wall.

 

If your going to stud andcover the morter, your ok. But if you are not going to cover the walls, the morter will fall out in a few years.